C-terminals of amino acid sequences that are homological to fibrinogen chains, together belong to family of FRED domains. FRED domains are engaged in protein protein interactions, like in fibrinogen and angiopoietins or bind carbohydrate, like in mammal ficolins. FRED domain spread between mentioned proteins by gen duplications and exon shuffling during evolution of multicellular animals. There are 24 genes in human DNA in which characteristic for FRED sequence is coded. Functions of many products of 24 genes still are not known.